​​​​​​​Are fidget spinners tools or toys?

Are fidget spinners tools or toys?

A fidget spinner craze is sweeping the United States. People of all ages are flicking the devices, which come in all manner of shapes, colors and materials. The gadgets follow a long line of toy fads, from Hula-Hoops and Pokémon cards to Silly Bandz. Some people argue that spinners relieve stress, anxiety and even symptoms of attention-deficit/hyperactivity disorder (ADHD). However, some schools have banned the mesmerizing devices for being too distracting. So, are fidget spinners annoying toys or therapeutic tools? Science suggests that they can be both. — Kathryn Hulick

Many people would say pure water tastes like nothing. But then how would mammals know that what we’re drinking is water? Tongues do detect water, a new study shows — and they do so by sensing acid. Bicarbonate-rich saliva is slightly basic. Drinking water washes the saliva away. An enzyme instantly kicks in to replace the bicarbonate ions. As a side effect, it produces protons, making local saliva more acidic. The tongue’s sour-sensing cells detect that acid. So our tongues detect water by sensing sour. But detection and flavor aren’t the same, so water still “tastes” like nothing. — Bethany Brookshire

Long ago, the Arctic Ocean was a huge freshwater lake. Precisely how and when this lake became the world’s northernmost ocean hadn’t been clear. A new analysis describes what allowed the Atlantic’s water to overwhelm that massive lake. Some 35 million years ago, a land bridge separating it from the salty Atlantic Ocean began sinking. Eventually, the bridge sank far enough that the Atlantic’s seawater started overrunning into the lake. But even that wasn’t enough, by itself, to tip the scales right away and transform the lake into an ocean. — Beth Geiger